Quick change roller die assembly



y 7, 1964 H. s. LANDERS 3,139,844

QUICK CHANGE ROLLER DIE ASSEMBLY Filed June 15, 1962 2 Sheets-Sheet 1 HARVEY S. LANDERS INVENTOR.

ATTORNEY y 7, 1964 H. s. LANDERS 3,139,844

QUICK CHANGE ROLLER DIE ASSEMBLY Filed June 13, 1962 2 Sheets-Sheet 2 HARVEY S. LANDERS INVENTOR.

ATTORNEY United States Patent 3,139,844 QUICK CHANGE ROLLER DIE ASSEMBLY Harvey S. Lauders, 207 E. Broadway, Fort Worth, Tex. Filed June 13, 1962, Ser. No. 202,117 3 Claims. (Cl. 107-14) This invention relates to pellet mills of the type where a cylindrical die rotates about rollers for compressing and extruding bulk material, for example, feed for livestock. Particularly, the invention is directed to improvements in quick change roller die assemblies such as described in my prior Patent No. 2,981,212 which issued April 24, 1961.

The die assembly of the referred to patent is generally comprised of a stationary main shaft, rollers mounted on an extending end of the shaft, an inner drive sleeve or quill around the shaft, and a cylindrical die mounted on the inner drive sleeve and positioned around the rollers for coaction therewith. The roller die assembly is removably mounted in an outer drive sleeve by means of a large elongate tapered nut threadedly mounted on the inner end of the inner drive sleeve and in wedging contact with the outer drive sleeve. While the elongate tapered nut serves its intended purpose, it has been found that the same requires considerable manual force to install and remove. Applying such manual force is sometimes time consuming and thereby tends to defeat the stated purpose of the invention of the patent, namely, quick removal and replacement of the roller die assembly.

An object of the invention is to provide power means for engaging and disengaging roller die assemblies in pellet mills.

Another object is to provide automatic means stopping rotation of the die in pellet mills when power means is applied for engaging and disengaging die assemblies.

These and other objects of the invention will become apparent from the following description and the accompanying drawing, wherein:

FIGURE 1 isa vertical longitudinal center section, taken on line 11 of FIGURE 3, of a pellet mill showing the present power means comprising a part thereof.

FIGURE 2 is a fragmentarily elevational and partly sectional view of the removable roller die assembly.

FIGURE 3 is an end elevational view, partly broken away, of the bracket member supporting one end of the main shaft and showing worm and gear means employed when engaging and disengaging the removable roller die assembly, and

FIGURE 4 is a wiring and schematic view including the prime mover and automatic safety switch.

The pellet mill shown in FIGURE 1 includes an inner or rear vertical wall 10, a bell housing 11 on the outer face thereof and which housing includes an outer or front wall 12 parallel with the first said wall. To those versed in the art it will be obvious that the various components may be assembled by means of cap screws or other screws, not shown.

Extending through the two walls and 12, and mounted in bearings 13, there is an outer drive sleeve 14 having a driven gear 15 therearound. The gear 15 is keyed to the sleeve as indicated at a. Beneath the gear 15 and parallel with the axis thereof there is a drive shaft 16, one end of which is journaled in a boss 17 within the housing 11 adjacent the front wall 12, whereas the remaining end is journaled in and extends through the rear wall 10. A drive pulley 18 is mounted on the extending end of the shaft and a pinion gear 19 is mounted on the same shaft to mesh with the driven gear 15.

Referring now to the removable roller die assembly 20, there is an inner drive sleeve 21, a circular flange 22 integral with one end thereof, and a cylindrical die 24 mounted on the flange. A stationary main shaft 25 ex- 3,139,844 Patented July 7, 1964 3 tends through inner drive sleeve 21 and the die 24, the

" directed central sleeve 30, which sleeve is keyed to the main shaft 25 as indicated at b. An outer plate 31 centrally mounted on the main shaft 25, and held in place by a nut 32, receives the extending ends of the stub shafts 28 for retaining the rollers 26 in place. Just inwardly of the inner plate 29, the main shaft 25 is shouldered at 33 for retaining bearings 34 received in a counterbore 35 in the end of the inner drive sleeve 21. Inwardly of the bearings 34 and slidably mounted on the main shaft 25 there is a bearing adjusting sleeve 36 which is held in place by a nut 37 threaded on said main shaft at a location within the inner drive sleeve 21.

The inner surface of the outer drive sleeve 14 adjacent the forward wall 12 is tapered, as at 38, to receive a correspondingly tapered outer surface on the inner drive sleeve 21 as indicated at 39. The two sleeves 14 and 21 are keyed to each other along their tapered surfaces as indicated at c. The referred to tapered surfaces, together with sliding contact at their inner ends, assure concentric alignment of the roller die assembly 20 in the pellet mill.

On the remaining surface of the rear wall 10 there is a hollow bracket member 40 having a vertical end wall 41 spaced from said rear wall and the end wall includes a circular flanged support 42 received in an opening 43. The main axle 25 extends through the flange support 42 where the extending end of the axle is held in place by a nut 44. This end portion of the axle 25 is tapered, as at 45, and is keyed, as at d, to prevent rotation of the axle when the mill is in operation. Inwardly of the bracket wall 41 and integral with the support 42 there is a radial flange 46, the purpose of which is to receive the inner ends of shear pins 47 extending through said wall. Also, integral with the support 42 and inwardly of the flange 46 there is a cylindrical bearing surface 48 for rotatably supporting a geared assembly nut Stl. By reason of the external threads on the geared nut 50, this element may be referred to as a threaded sleeve. The inner end of the nut 50 has square threads, not numbered, for threadedly engaging corresponding threads in the inner end of the inner drive sleeve 21. It is to be noted that the gear nut 50 is capable of rotation between the inner end of the outer sleeve 14 and a vertical surface of the flange 46. It is also pointed out that the described arrangement of shear pins 47 and mounting of the flange support 42 accommodates longitudinal expansion of the two drive sleeves 14 and 21 in the event of excessive heat.

The outer circumference of the geared nut 50 has teeth 51 for coaction with a worm 52 on a shaft 53, one end of which is connected with a reduction gear train, the housing of which is shown at 54. A reversible motor 55, which drives the gear train, has a projecting portion 56' on the upper area of its housing for pivoted connection, by means of a pin 57, with laterally extending arms. 58 on the bracket member 40. Mounted on the gear train housing 54 there is a bracket 56 supporting the extending end of the worm shaft 53. The extending end of the bracket 56 is connected with a crank shaft 59, one end of which is journaled in a boss 60 on the adjacent surface of the mill rear wall 10, and the remaining end extends through the bracket wall 41 where it is provided with a lever 61. Thus, operation of the lever raises and lowers the bracket 56 for engaging and disengaging the worm 52 and gear teeth 51.

A boss 62 on the lever 61 is arranged to contact and open a microswitch 63 on the bracket member 40 when the worm 52 and gear teeth 51 are engaged. The micro switch 63 is connected in a circuit, FIGURE 4, supplying power to a prime mover operating the pellet mill. Other than the switch 63 and its coaction with the lever 61 and crank 59 engaging and disengaging the worm 52 geared nut 50, the circuit illustrated in FIGURE 4 is conventional or may be varied by those having ordinary skill in the art. In the example shown, the prime mover 64 is an electric motor, the drive pulley 65 of which is connected with the pulley 18 of the pellet mill by belts 66. The prime mover 64 is connected with a power source S by leads 67 and 68, one of which leads 67 includes the switch 63. The switch 63 shown is of the single pole double throw type and makes contact with the reversible motor 55 by a lead 69, and the circuit is completed by an additional lead 70 by connection with one of the first described leads 68. As shown schematically in FIGURE 4, the armature 72 of the switch 63 is operated by a lever 73 which, in turn, is connected with the button 74 of the switch. Thus, as a safety measure, the outer drive sleeve 14 will not turn when the roller die assembly is being removed or installed. To install or remove the roller die assembly 20, the nut 44 at the tapered end 45 of the main shaft 25 is removed and the reversible motor 55 is actuated in a direction to turn the geared nut 50 in the required direction through the medium of the worm 52. During the regular milling operation, the lever 61 is turned in a direction to raise the worm 52 from the gear teeth 51, and at which time the microswitch 63 is in its closed position. Rotation of the geared nut 50 turns the square threads thereon in a direction to either move the inner drive sleeve 21 either inwardly or outwardly as required.

The invention is not limited to the exemplary constructions herein shown and described, but may be made in various ways within the scope of the appended claims.

What is claimed is:

1. A pellet mill for use in the preparation of feed for live stock comprising a housing having a front wall, a rear wall, and a hollow bracket positioned externally of the rear wall, said bracket having a wall portion substantially parallel to said rear wall, a first sleeve extending horizontally between openings therefor in the front and rear walls, the rearward end of said first sleeve extending rearwardly beyond said rear wall, said first sleeve being journaled in bearings therefor in the front and rear walls and having drive means thereon whereby it is adapted to be rotated about its axis, a second sleeve of relatively smaller diameter removably inserted in said first sleeve from its forward end and rotatable therewith, said second sleeve having an enlarged, cylindrical forward end portion positioned externally of the housing and having extrusion dies in the peripheral wall thereof, said second sleeve having a cylindrical rearward end portion and a long tapered forward end portion for engagement with correspondingly shaped inner surfaces of said first sleeve whereby said first and second sleeves are positively aligned concentrically and coaxially, a fixed shaft of relatively smaller diameter arranged concentrically and coaxially within said second sleeve and extending beyond opposite ends thereof, a pair of diametrically opposed rollers journaled on stub axles having means connecting them to the forward end of said shaft, eccentrically thereof, whereby said rollers are positioned in opposing relation to said dies, said shaft having its forward end portion journaled in bearings therefor in the forward end portion of said second sleeve whereby said first and second sleeves are movable rotatively about said shaft, said shaft extending rearwardly of said second sleeve and having a tapered rearward end portion which is passed through an opening therefor in a supporting block connected by shear pins to said wall portion of said bracket, said tapered rearward end portion being secured against rotation relative to said supporting block and having a nut threaded on its extreme end rearwardly of said tapered rearward end portion whereby said shaft is removably secured in said housing, a third sleeve of relatively smaller diameter than said second sleeve loosely surrounding said shaft and positioned rearwardly of said first and second sleeves, said third sleeve having an internally enlarged rearward end portion received on a cylindrical boss on said supporting block and having an externally threaded forward end portion in threaded engagement with an internally threaded rearward end portion of said second sleeve whereby said second sleeve is removably secured in said first sleeve and is positively displaced axially relative thereto upon turning said third sleeve, and an external enlargement on said third sleeve intermediate its ends having means thereon for turning said third sleeve.

2. The structure of claim 1, the external enlargement on said third sleeve intermediate its ends having a gear coextensive with its peripheral surface, a worm gear arranged transversely of said shaft above the external enlargement on said third sleeve and normally disengaged from said gear during the operation of the pellet mill, an electric motor and speed reduction gears acting on said worm gear to drive it, means on said bracket pivotally supporting said worm gear, said electric motor, and said speed reduction gears for pivotal adjustment about an axis parallel to the longitudinal axis of said shaft whereby said worm gear is adapted to be operatively engaged with said first mentioned gear and disengaged therefrom, and a crank lever acting on said bracket and said means pivotally supporting said worm gear, said electric motor, and said speed reduction gears to advance and retract said worm gear relative to said first mentioned gear.

3. The structure of claim 2, and a second electric motor having drive means operatively connecting it to said first sleeve whereby said first sleeve is adapted to be rotated about its axis by operation of said last mentioned motor, said last mentioned motor being connected in an electrical circuit which includes a switch acted on by said crank lever in one position thereof whereby said electrical circuit is automatically opened to cut off the supply of electricity to said last mentioned motor, to thereby stop the pellet mill, in response to movement of said crank lever preparatory to removing from the pellet mill the assembly comprising said shaft and said second sleeve.

References Cited in the file of this patent UNITED STATES PATENTS 1,327,129 Wolff Ian. 6, 1920 1,974,249 Olson Sept. 18, 1934 2,420,855 Bogart May 20, 1947 2,470,897 Niederhiser May 24, 1949 2,704,426 Macaulay Mar. 22, 1955 2,981,212 Landers Apr. 25, 1961 3,044,391 Pellett July 17, 1962 a; w h 

1. A PELLET MILL FOR USE IN THE PREPARATION OF FEED FOR LIVE STOCK COMPRISING A HOUSING HAVING A FRONT WALL, A REAR WALL, AND A HOLLOW BRACKET POSITIONED EXTERNALLY OF THE REAR WALL, SAID BRACKET HAVING A WALL PORTION SUBSTANTIALLY PARALLEL TO SAID REAR WALL, A FIRST SLEEVE EXTENDING HORIZONTALLY BETWEEN OPENINGS THEREFOR IN THE FRONT AND REAR WALLS, THE REARWARD END OF SAID FIRST SLEEVE EXTENDING REARWARDLY BEYOND SAID REAR WALL, SAID FIRST SLEEVE BEING JOURNALED IN BEARINGS THEREFOR IN THE FRONT AND REAR WALLS AND HAVING DRIVE MEANS THEREON WHEREBY IT IS ADAPTED TO BE ROTATED ABOUT ITS AXIS, A SECOND SLEEVE OF RELATIVELY SMALLER DIAMETER REMOVABLY INSERTED IN SAID FIRST SLEEVE FROM ITS FORWARD END AND ROTATABLE THEREWITH, SAID SECOND SLEEVE HAVING AN ENLARGED, CYLINDRICAL FORWARD END PORTION POSITIONED EXTERNALLY OF THE HOUSING AND HAVING EXTRUSION DIES IN THE PERIPHERAL WALL THEREOF, SAID SECOND SLEEVE HAVING A CYLINDRICAL REARWARD END PORTION AND A LONG TAPERED FORWARD END PORTION FOR ENGAGEMENT WITH CORRESPONDINGLY SHAPED INNER SURFACES OF SAID FIRST SLEEVE WHEREBY SAID FIRST AND SECOND SLEEVES ARE POSITIVELY ALIGNED CONCENTRICALLY AND COAXIALLY, A FIXED SHAFT OF RELATIVELY SMALLER DIAMETER ARRANGED CONCENTRICALLY AND COAXIALLY WITHIN SAID SECOND SLEEVE AND EXTENDING BEYOND OPPOSITE ENDS THEREOF, A PAIR OF DIAMETRICALLY OPPOSED ROLLERS JOURNALED ON STUB AXLES HAVING MEANS CONNECTING THEM TO THE FORWARD END OF SAID SHAFT, ECCENTRICALLY THEREOF, WHEREBY SAID ROLLERS ARE POSITIONED IN OPPOSING RELATION TO SAID DIES, SAID SHAFT HAVING ITS FORWARD END PORTION JOURNALED IN BEARINGS THEREFOR IN THE FORWARD END PORTION OF SAID SECOND SLEEVE WHEREBY SAID FIRST AND SECOND SLEEVES ARE MOVABLE ROTATIVELY ABOUT SAID SHAFT, SAID SHAFT EXTENDING REARWARDLY OF SAID SECOND SLEEVE AND HAVING A TAPERED REARWARD END PORTION WHICH IS PASSED THROUGH AN OPENING THEREFOR IN A SUPPORTING BLOCK CONNECTED BY SHEAR PINS TO SAID WALL PORTION OF SAID BRACKET, SAID TAPERED REARWARD END PORTION BEING SECURED AGAINST ROTATION RELATIVE TO SAID SUPPORTING BLOCK AND HAVING A NUT THREADED ON ITS EXTREME END REARWARDLY OF SAID TAPERED REARWARD END PORTION WHEREBY SAID SHAFT IS REMOVABLY SECURED IN SAID HOUSING, A THIRD SLEEVE OF RELATIVELY SMALLER DIAMETER THAN SAID SECOND SLEEVE LOOSELY SURROUNDING SAID SHAFT AND POSITIONED REARWARDLY OF SAID FIRST AND SECOND SLEEVES, SAID THIRD SLEEVE HAVING AN INTERNALLY ENLARGED REARWARD END PORTION RECEIVED ON A CYLINDRICAL BOSS ON SAID SUPPORTING BLOCK AND HAVING AN EXTERNALLY THREADED FORWARD END PORTION IN THREADED ENGAGEMENT WITH AN INTERNALLY THREADED REARWARD END PORTION OF SAID SECOND SLEEVE WHEREBY SAID SECOND SLEEVE IS REMOVABLY SECURED IN SAID FIRST SLEEVE AND IS POSITIVELY DISPLACED AXIALLY RELATIVE THERETO UPON TURNING SAID THIRD SLEEVE, AND AN EXTERNAL ENLARGEMENT ON SAID THIRD SLEEVE INTERMEDIATE ITS ENDS HAVING MEANS THEREON FOR TURNING SAID THIRD SLEEVE. 